It has been shown that the larger the starting library diversity, the more likely a high affinity reagent will be selected without the need for affinity maturation (Vaughan, et al. (1996) Nat. Biotechnol. 14:309-314; Ling (2003) Comb. Chem. High Throughput Screen 6:421-432). However, due to the limited number of E. coli cells that can be feasibly grown, the largest libraries constructed for phage-display are on the order of 1×1010 members (Dower, et al. (1988) Nucleic Acids Res. 16:6127-6145; Sheets, et al. (1998) Proc. Natl. Acad. Sci. USA 95:6157-6162), which are stored frozen and subjected to freeze-thaw before selection. Ribosome-display, on the other hand typically starts with a freshly translated library with a diversity 100-fold greater (Pluckthun (2012) Methods Mol. Biol. 805:3-28; Hanes & Pluckthun (1997) Proc. Natl. Acad. Sci. USA 94:4937-4942), but requires more steps and effort if not automated.
Ribosome-display is described in US 2006/0177862 for use in the selection of antibodies, wherein ribosome-display complexes are encapsidated into a viral coat to protect the product from degradation. Further, US 2013/0210680 suggests the use of ribosome-display in amplifying a library of clones. Moreover, ribosome-display has been combined with other display technologies for screening the output from the ribosome-display rounds (Pelletier, et al. (1999) Nat. Biotechnol. 17:683-690) or for affinity maturation of phage-display selected pools (Groves, et al. (2006) J. Immunol. Methods 313:129-139; Groves & Nickson (2012) Methods Mol. Biol. 805:163-90; Finlay, et al. (2009) J. Mol. Biol. 388:541-558; Dufner, et al. (2006) Trends Biotechnol. 24:523-9). However, ribosome-display has not been integrated with phage-display as part of a primary selection scheme.